BYTETOOLS

Resize Image in CM

Resize an image to exact centimeters, millimeters or inches at a chosen DPI. Writes real print density metadata so photo software prints it true to size.

Drop an image to resize in cm, mm or inchesResized locally — never uploaded

What is the Resize Image in CM?

The ByteTools CM Image Resizer converts real-world print dimensions into pixels and resizes your photo to match.

  • Resize by cm, mm or inches instead of pixels
  • DPI presets: 96, 150, 300, 600 plus custom values
  • Writes real density metadata (PNG pHYs / JPEG JFIF)
  • Live pixel-dimension readout as you type
  • Aspect-ratio lock to avoid distortion
  • 100% private — photos never leave your browser

How to use the Resize Image in CM

  1. 1

    Drop an image into the upload area.

  2. 2

    Choose your unit — cm, mm or inches — and enter the width and height.

  3. 3

    Pick the print DPI (300 is the print standard).

  4. 4

    Check the computed pixel size, then download the resized file.

About the Resize Image in CM

The ByteTools CM Image Resizer converts real-world print dimensions into pixels and resizes your photo to match. Enter a size in centimeters, millimeters or inches, pick a print resolution (DPI), and the tool computes the exact pixel dimensions using the standard formula: pixels = size in inches × DPI. A 10 × 15 cm print at 300 DPI, for example, becomes 1181 × 1772 pixels.

Crucially, the exported file also carries the correct density metadata — the PNG pHYs chunk or JPEG JFIF density fields — so Photoshop, Word, printers and photo labs read the intended physical size instead of guessing. That is what plain pixel resizers miss, and why prints come out the wrong size.

It is made for print prep: passport and visa photos specified in mm, framed prints in cm, stickers, ID cards and school projects. Everything runs 100% locally in your browser; your photo is never uploaded.

Frequently asked questions

How do I convert cm to pixels for an image?

Divide the centimeters by 2.54 to get inches, then multiply by the DPI. At 300 DPI, 1 cm equals about 118 pixels, so a 4 × 6 cm photo becomes 472 × 709 pixels. This tool does that math live as you type.

What DPI should I use for printing?

300 DPI is the standard for sharp photo prints and documents at reading distance. 150 DPI is acceptable for large posters viewed from farther away, and 600 DPI only helps for fine line art. Screen-only images can stay at 96 DPI.

Why does my image print at the wrong size even after resizing?

Because most resizers change only the pixels and leave the file's density metadata unset, so software falls back to 72 or 96 DPI and prints it too large. This tool writes the DPI you chose into the file itself, which is what print software actually reads.

Does resizing to cm change my image quality?

The image is resampled to the new pixel dimensions with high-quality interpolation. Shrinking is visually lossless; enlarging a small photo to a big print size will soften it, because new pixels must be interpolated — start from the highest-resolution original you have.

Can I use this for passport photo sizes like 35 × 45 mm?

Yes — switch the unit to mm, enter 35 × 45 at 300 DPI, and you get the standard 413 × 531 pixel file with correct density metadata. For cropping the face to regulation position too, use the dedicated Passport Photo Maker.

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